Engine starter



Aug. 25, 1931. w. L. )MCGRATH 1,820,397

[ENGINE STARTER Filed Sept. 4, 192 5 2 Sheets-Sheet 1 Aug. 25, 1931.

w. MCGRATH ENGINE STARTER Filed "s'epv; 4, 1925 2 She ets-Sheet 277945726155 Mxzm,

Patented Aug. 25, 1931 UNITED STATES PATENT orrlcE WILLIAM L. MCGRAT'H,OF ELMIRA, NEW YORK, ASSIGNOR TO ECLIPSE MACHINE GOM- PANY, OF ELMIRAHEIGHTS, NEW YORK, A CORPORATION OF NEW YORK ENGINE STARTER IApplication filed September 4, 1925. Serial No. 54,433.

My invention relates to an enginestarter, and pertains more particularlyto the drive or transmission between a prime mover such as anelectricmotor and a member of the engine to be started such as theflywheel thereof. The drive in which my invention is embodied is of theradial shift type in which a rotatable member or pinion which is adaptedto transmit the torq'ne of the starting motor of the prime mover orstartingv motor is positioned in the plane of the engine member andadapted to be brought into operative engagement or nesh withflsuchengine member at the time of the cranking operation. i r

The object of my invention is to provide a drive or transmission of thistype which shall be simple in construction and'efiicienti Referring tothe particular embodiment of my invention as herein shown, the'primemover is here in the form of an electricstarting motor land the drive isof'the direct type and accordingly the armature shaft 2 of the motor isextended and the drive or transmission is mounted thereupon and driventhereby.

The. drive includes a rotatable member which is here in the form of asleeve 3 which is mounted upon the armatureshaft and operativelyconnected therewith, preferably in yielding manner as by means of the.drive spring 4. This drive spring is conv nected at its oppositeendswith the drive head 5'secured to the armature'or power shaft 2 bymeans of the bolt:6 and tothe drive head portion 7 of the screw shaft bythreaded portion 9 and a smooth portion 10 and the same is provided atits inner end adjacent the motor with an abutment or stop nut 11. Adriving member which is inthe form of a pinion 12 is loosely mountedupon the said smoothor plain portion ofithe shaft which portion islocated between said abutment and the screw threaded portion of thesleeve. A screw member ornut 13 is threaded upon the screw threadedportion of the sleeve for longitudinal movement to the right (Fig. 1)when the shaft and sleeve arerotated, to thereby engage the left handface of the pinion 12 and clamp such pinion against the abutment tothereby drivingly connect the pinion with the sleeve. The normalposition of the screw member or nut 13 is at the outerf ends' of thescrew threads and away from the pinion 12 as shown in Fig. 1. 1

A frame is mounted to swing or oscillate with the axis of the motorarmature as a center and in. the present instance, such frame is mountedupon the pinion 12. To this end, the frame comprises two parallel plates14' having at their upper end an opening to receive opposite sides ofthe eriphery of the pinion 12. As shown in igure 1, the pinion teeth donot extend all-the way across the body of the pinion, but are cutaway-at their opposite ends and such body portionis also recessed as at15 in order toprovide peripheral bearings for these plates 14;. Theseplates are held together in proper spaced relationship by means of thebolts 16. In the lower portion of the frame, there is journaled a secondor transmitting pinion 17 loosely mounted upon a center shaft 18 whichis preferably provided with a bushin 19. Theparts are held in place bymeans 0? another bolt 20.

The pinion 17 is constantly in mesh with the driving pinion, but isnormally out of mesh or driving relationship with the 'engine member orgear, such as the flywheel indicated at 21. This normal position of thedrive is indicated in Fig. 2, but upon the operation of'the startingmotor the pinion 17 will automatically swing to the left and intermeshwith the flywheel, as shown in Fig. 3, as an incident to and the result.of the transmission of torque through the driv ing pinion l2.

Describing av cycle of operation of the parts and beginning with thesame in their normal position, shown in Figs. l and 2, when it isdesired to crank the engine, the starting motor 1 is energized with theresult that its armature shaft and the screw sleeve are rotated in aclockwise direction as indicated by the arrow in Fig. 3. This rotationof the sleeve causes a longitudinal movement of the screw-member or nut13 to the right and against the left-hand face of the driving member orpinion 12. This causes a-clamping of such pinion against the abutment 11and clamps such pinion in driving relationship with the screw sleeve.The driving pinion 12 thereupon starts to rotate with the sleeve and asit is constantly in mesh with the transmitting pinion 17, such pinionwill be swung to the left (Fig. 3) and into mesh with the flywheel, asshown in Fig. 3. So long as the torque is being transmitted from thestarting motor to the engine, the transmitting pinion will remain inmesh and will rotate the flywheel and crank the engine. lVhen the enginestarts and operates under its own power, the excess speed of rotation ofthe flywheel transmitted from pinion 17. to pinion 12 will cause the nut13 to be rotated faster than it is being rotated by the screw sleeve,with the result that the nut will be moved to the left (Fig. 1) and thepinion 12 will be unclamped so that it will be free and unable totransmit torque in either direction. Thereupon, the entire frame and thetransmitting pinion 17, being thus free, will swing away from theflywheel back to normal position as shown in Fig. 2, and will remain inthat position, in this instance, by gravity, until the next startingoperation. l.\l v construction thus avoids the use of complicatedmechanism intended to insure and maintain disengagement of the pinionfrom the flywheel gear after the engine has started.

I claim:

1-. In an engine starter drive of the radial shift type, the combinationwith a rotatable member of the engine to be started, of a rotatabledriving shaft, a rotatable driving member normally loosely mountedthereon, means actuated automatically by the rotation of such drivingshaft for operatively connecting the driving member to the driving shaftwhen the latter is rotated, and a rotatable member constantly inoperative relationship with the driving member and normally out ofoperative relationship with the engine member, but mounted to swing intosuch operative relationship by the torque transmitted through thedriving memher and being constantly free to swing into and out of suchrelationship according to direction of torque application thereto.

2. ln an engine starter drive of the radial shil'l type, thecombination, with a rotatable member of the engine to be started, of arotatable driving shaft, a rotatable driving member normally looselymounted thereon, means actuated automatically by the rotation of suchdriving shaft for operativcly connecting the drive member to the drivingshaft when the latter is rotated, a swinging frame carried by suchdriving member, and a rotatable member journalled in such frame andconstantly in operative relationship with the driving member andnormally out of operative relationship with the engine member butadapted to swing into such operative relationship by the torquetransmitted through the driving memberand constantly free to swing intoor out of such operative relationship according to direction of torqueapplication thereto.

3. In an engine starter drive of the radial shift type, the combination,with a rotatable member of the engine to be started, of a rotatabledriving shaft, a. rotatable driving member normally loosely mountedthereon and rotatable in a fixed plane, means actuated automatically bythe rotation of such driving shaft for clamping the driving m'emher tothe driving shaft when the latter is rotated, such means comprising aclamping device mounted on the shaft for longitudinal movementtherealong when such shaft is rotated and into clamping engagement withsaid driving member, and a driving connection between the driving memberand the engine member which connection is swung radially by torqueapplied to said driving member.

4. In anengine starter drive of the radial shift type, the combination,with a rotatable member of the engine to be started, of a rotatabledriving shaft, a rotatable driving member normally loosely mountedthereon and rotatable in a fixed plane, means actuated automatically bythe rotation of such driving shaft for clamping the driving memher tothe driving shaft when the latter is rotated, said shaft having externalscrew threads and such means comprising a screw member threaded on saidthreads of the shaft for longitudinal movement along the shaft-and intoclamping engagement with said driving member to rotarily connect thelatter to the shaft, and a driving connection between the driving memberand the engine member which connection is swung radially by torqueapplied to said driving member.

In an engine starter drive of the radial shift type, the combination,with a rotatable member, of the engine to be started, of a rotatabledriving shaft, a rotatable driving member normally loosely mountedthereon and rotatable in a fixed plane, means actuated automatically bythe rotation'of such driving shaft for clamping the driving member tothe driving shaft when the latter is rotated, said shaft having externalscrew threads and such means comprising a screw member threaded on saidthreads of the shaft for longitudinal movement along the shaft and intoclamping engagement with said driving member to rotarily connect thelatter to the shaft, and a driving connection constantly in drivingrelationship with said driving member and mounted to swing into drivingrelationship withthe engine member when the drivingnienibei"transmitstorque and by means of that torque, 7

6. In an engine starter drive of the radial shift type, the combination,with a rotatable member ofthe, engine to be started,*of a rotatabledriving shaft, a-rotatable driving member normally loosely mountedthereon androtatable in a fixed plane, means actuated automatically bythe rotation of such driving shaft for clamping the driving member tothe driving shaft when the latter is rotated, said shaft having anabutment on one side of the driving member, said means comprising aclamping device located on the other sideofthe driving member andadapted to clamp the latter against said abutment to drivin'gly connectthe driving member to the shaft, and a driving connection between thedriving member and the enginemember. I

.7. In an engine starterdrive of the radial shift type, theeombinatioinwith a rotatable member of the engine tobe started, (if a'rotatable driving shaft, airotatable'driving membernormally looselymounted thereon and rotatable in a fixed plane, means actu atedautomatically by the rotation of'such driving shaft for clamping thedriving mem ber to the driving shaft when thelatter is rotated, saidsha-fthaving an abutment on i one side of the drivlng member, said meanscomprising a clamping device located on the otherside of the drivingmemberand adapted to clamp the latter against saidabutment to drivinglyconnect the driving member to the shaft, and g a driving connectionconstantly in driving relationship with said driving member and mountedto swing'into driving relationship'with the engine. member when thedriving member transmits torque. 7, I

r 8. In an engine starter drive of the radial shift-type, thecombination, with a rotatable member of the engine to be started,'of arotatable driving shaft, a rotatable driving member normally looselymounted thereon and rotatable in a fixed plane, means actuatedautomatically by the rotation of such driving shaft for clamping. thedriving mem ber tothe driving shaft when the latter is rotated, saidshaft having exterior screw threads on one side of the driving member.

and an abutment on the other side thereof,

matically by the rotation of the d-ri'vin shift type, the combinationwith a gear of the engine to be started, of a rotatabledriving shaft,,adriving pin-ion normally loosely mounted thereon, means actuatedautomatically by the rotation of the driving shaft for oper ativelyconnecting; the pinion to the .shaft in driving relationship when suchshaft ,is rotated, and a transmitting pinion between the driving pinionand theengine gear, such transmitting pinion being shifted radially bythe torque transmitted throughthe driving pinion and being constantlyfreeto be shifted radially in either direction according to direction oftorqneapplication thereto. 3 p a 10. In an engine starter drive of theradial shift type, the combination with a gear of the engine to bestarted, ofa rotatable driving shaft, a-driving pinion normally looselymounted thereon, means actuated automati cally by the rotation of thedriving shaft for operatively connecting thepinion -to the shaft indriving relationship when such shaft is-rotated, and a second pinionconstantly meshing with the driving pinion and constantly located intheplane of the engine gear, said second pinion being shiftable ra-dially into engagement with the engine gear by the torque transmittedthrough the first said pinion and being constantly free to be shiftedradially ineither direction according to direction of torque applicationthereto.

11. In an engine starter drive of the radial Shift type, the combinationwith a gear .of the engine to be started, of a rotatabledriving shaft, adriving pinion normally looselymounted thereon, means actuated auto-' gshaft for operatively'connectingthe pinion to the shaft in drivingrelationship when such shaft is rotated, 'a-fswinging frame mounted onsaid driving pinion, and a second pinion mounted inv such frame andconstantly in mesh with the driving pinion, such second pinionbeingconstantly free to be shifted radially in either directionaccording to then direction of torque application thereto and adapted tomesh with the engine gear when swung thereinto by the'tor'que applied togear. a i I :12. In an engine starter drive of the radial shift type,the combination witha gear of the engine to be started, ofa power shaft,

the first pinion andto rotate said engine loosely mounted on the sleeveto rotate in a tixed plane. a screw member threaded on the sleeve forlongitudinal movement thereon to clamp the pinion thereto, and a drivingconnection between the pinion and the engine gear.

13. In an engine starter drive of the radial shift type, the combinationwith a gear of the engine to be started, of a power shaft, a sleevemounted on the shaft and rotatably connected therewith, a pinionnormally loosely mounted on the sleeve to rotate in a fixed plane, ascrew member threaded on the sleeve. for longitudinal movement thereonto clamp the pinion thereto, and a second pinion constantly meshing withthe first pinion and normally out of mesh wlth )the engine gear butmounted to swing into mesh with such gear when the first pinion isclamped to the sleeve.

it. In an engine starter drive of the 'radlal shift type, thecombination with a gear of the engine to be started, of a power shaft, asleeve mounted on the shaft and rotatably connected therewith, a pinionnormally loosely mounted on the sleeve to rotate in a fixed plane, ascrew member threaded on the sleevefor longitudinal movement thereon toclamp the pinion thereto, a frame pivotally mounted upon the pinion, anda second pinion journalled in such frame and constantly in mesh with thefirst pinion and normally out of mesh with the engine gear but adaptedto be swung into mesh therewith when the first pinion is clamped to thesleeve.

1:). In an engine starter drive of the radial shift type, thecombination with a gear of the engine to be started, of a power shaft, asleeve mounted on the shaft, a yielding driving connection between theshaft and sleeve, said sleeve having a plain portion and a screwthreaded portion, a pinion loosely mounted on said plain portion torotate in a fixed plane, a nut threaded on the screw threaded portionfor longitudinal movement against the pinion to clamp it drivingly tothe sleeve when the shaft and sleeve are rotated, and a second pinionconnecting between the first pinion and theengine gear.

16. In an engine starter drive of the radial shift type, the combinationwith a gear of the engine to be started, of a rotatable driving shaft, adriving pinion normally loosely mounted thereon, means actu atedautomatically by the rotation of the driving shaft for clamping thepinion to the shaft in driving relationship when such shaft is rotated,a frame mounted directly on the body of the pinion to swing upon thepinion, and a second pinion journalled in such frame and constantly inmesh with the driving pinion but adapted to mesh with the engine gearwhen swung thereinto and to rotate the same.

17. In an engine starter drive of the radial shift type, the combinationwith a gear of the. engine to be started, of a rotatable driving shaft,:1 driving pinionnormally loosely mounted thereon, means actuatedautomatically by the rotation of the driv' ing shaft for coactingdirectly with the side face of said pinion to clamp the pinion to theshaft in driving relationship when such shaft is rotated, the peripheryof the body of such pinion on its opposite sides being formed withannular bearing surfaces, a frame mounted to swing upon such surfaces ofthe pinion, and a second pinion journalled in such frame and constantlyin mesh with the driving pinion but adapted to mesh with the engine gearwhen swung thereinto and to rotate the same.

18. In an engine starter driveof the. radial shift type, thecombination, with a ro tatable member of the engine to be started, of arotatable driving shaft, a rotatable driving member normally looselymounted thereon, a driving connection for operatively connecting betweensaid two members and constantly free to be swung radially for making orbreaking such operative connection, and combined means located in theline of transmission of torque for automati :ally connecting the drivingmember to the driving shaft and for radially shiftingsaid drivingconnection into engagement with the engine member by means of the torqueso transmitted to the driving member.

19. In an engine starter drive of the radial shift type, thecombination, with a rotatable member of the engine to be started, of arotatable driving shaft, a rotatable driving member normally looselymounted thereon, a driving connection for operative- 1y connectingbetween said two members and constantly free to be swung radially formaking or breaking such operative connection, and combined means forfirst automatically connecting the driving member to the driving shaftand for then radially shifting said driving connection into engagementwith the engine member by means of the torque transn'iitted through thedriving member.

20. In an engine starter drive of the radial shift type, the combinationwith a rotatable member of the engine to be started, of a rotatabledriving shaft, a rotatable driving member normally loosely mountedthereon, means actuated automatically by the rotation of such drivingshaft for operatively connecting said driving member to the drivingshaft when the latter is rotated, a driving connection between thedriving member and the engine member mounted to stand normally in idleposition and to be swung radially into active position by the torquetransmitted through said driving member, a source of power, and ayielding driving connection between said source of power and saidrotatable driving shaft,

' 21. In an engine starter drive of the radial shift type, thecombination with a rotatable member of the en 'ie to be started and asource of power, 0 a rotatable driving shaft, a torsional yieldingconnection between said driving shaft and said source of power, arotatable driving member norma 1y loosely mounted on said driving shaft,means on said driving shaft and actuated automatically by the rotationthereof for operatively connecting the driving member to the drivingshaft when the latter is rotated, and a rotatable member constantly inoperative relationship with the driving member and normally out ofoperating relationship with the engine member but mounted to swing intosuch operative rela-.

tionship by the torque transmitted through the driving member.

22. In an engine starter drive of the radial shift type, the combinationwith a gear .of the englne to be started, of a rotatable drive shaft, adriving pinion normally loosely mounted thereon, means actuatedautomatically by the rotation of the driving shaft for clamping thepinion to the shaft in driving relationship when such shaft is rotated,a frame mounted directly on the body of the pinion to swing upon thepinion, and a second pinion journaled in such frame and constantly inmesh with the driving pinion but adapted to mesh with the engine gearwhen swung thereinto and, to rotate the same, said driving pinion beingconstantly located in the plane of the engine gear and saidsecond'pinion being constantly free to be shifted radially in eitherdirection according to the direction of torque application thereto.

WILLIAM L. MCGRATH.

